External combustion motor



March i0, i942. G, N; HANsoN 2,275,756

EXTERNAL COMBUSTION MOTOR Filed 26, 1940 2 Sheets-Sheet l Eufemia?" March 10, 1942. G, N, HANSON 2,275,756

EXTERNAL COMBUSTION MOTOR 55077 qys Patented Mar. io, 1942 UNITED STATES PATENT OFFICE EXTERNAL coMUs'rloN Mo'roa Glen N. Hanson, Minneapolis, 'application August 26, 1940, serial No. 354,153

' (c1. so-44) 8 Claims. This invention relates to external combustion @engines It is an object ofthe present invention to provide a novel and improved type of external combustion engine which is of simple and inexpensive construction and can be operated economicallyV to produce power. Another object isto provide a novel and improved type of two cycle external combustion engine wherein two combustion chambers are provided which alternately act to drive apiston ward the closed end of the cylinder during the next revolution of the crank shaft.

Another object is' to provide in an external combustion engine, novel means for scavenging the products of combustion and for placing the Vcharge under some initial compression through the supply ofY combustion air to a combustion chamber. l Y

The. objects and advantages of the invention will more fully appear from the following description made in connection with the accompanying drawings, wherein like reference char-- acters refer to the same or similar parts throughout the several views, and in which,

Fig. 1 is a vertical transverse sectional view through an engine embodying the invention;

Fig. 2 is a view in side elevation of the same engine; Y r

Fig. 3 is a detail illustrating certain of the cams and other parts for operating certain of the valves of the engine:

Fig. 4 is a diagram illustrating the two cycl operation of the engine; and c Fig. 5 is a partial view similar to Fig. 1V but showing a valve in head engine construction which is a modied form of the invention.

Referring irst to the embodiment of the invention shown in Figs. 1 to 4 inclusive,'the engine case is designated by the letter A and it is constructed to form a cylinder 6 a left hand combustion chamber 1, and a right hand combus- ,Y tion chamber 8, these two combustion chambers being substantially alike but located preferably at opposite sides of the cylinder 6. A top plate 9 closes upper ends of the two combustion chambers 'I and 8 While the lower ends of the comlll carries a wrist pin 20 to which, a connecting rod the piston approaches the end of the stroke to- 2l is connected in the usual inanner, the said connecting rod being connected in the usual manner to one crank of a crank shaft 22. A

crank case 23 is bolted/to the engine case A in the usual manner to house the crank shaft 22 and other working'parts..

Valves 24 and 25, which rwill be designated transfer valves, control the two ports I3 and I4 respectively, these valveslhaving stems 26 and 21 respectively. These valv'e stems 26 and 21 are guided by sleeve-like portions formed in the engine casing A and project downwardly therefrom into oil retaining cups 28 and 29 which r closed so as to prevent communication between vthe combustion chambers 1 and 8vand the head and the stems 40 and 4I are guided in these casbustion chambers are closed by walls I0 and II. 55

ings and above the casings the stems carry caps 44 and 45, coil springs 46 and 41 respectively being interposed between the said caps and the .casings 42 and 43 respectively to normally hold duit 49 which is connected to the two ends of the air casings 42 and 43 and the blower 48 acts to supply air under pressure to the two\ combustion chambers 1 and 8 when the air admission valves 38 and 39 are open. In order to drive the blower conveniently the crank shaft 22 outside the -haust casings 60 and 6| are formed which guide the stems 58 and 59 of exhaust valves 56 and 51 and caps 62 and 63 are carried by the lower ends of the stems and coil springs 64 and 65 respectively react between these cap 62 and 63 and the exhaust casings 60 and 6| respectively to normally hold the exhaust valves 56 and 51 closed. Exhaust pipes 66 and 51 are connected to the respective casings 60 and 6| leading to atmosphere.

Within the combustion chambers 1 and 8 and ldisposed between the air intake valves 38 and 39 and the exhaust valves 56 and 51 respectively of the combustion chamber are confining hoods 68 and 69respectively in the shape of truncated hollow cones which flare inwardly toward their ends adjacent the air intake valves 38 and 38.

Igniters shown as spark` plugs 10 and 1| are provided for the respective combustion chambers 1 and 8 and these igniters are preferably located within the respective hoods 68 and 69. Fuel spray nozzles 12 and 13 respectively are'also provided for the two combustion chambers Tand 8, these spray nozzles being also preferably mounted to discharge within the hoods 68 and 68. A twin fuel injector 14 of any standard type, the details of which are not illustratedyis operated from somerotating .part of the engine, the saidv in jector being shown in Fig. 2, and through conduits 15 and 16 respectively, the twin injector supplies fuel tothe respective-fuel nozzles 12 and 13.

The various transfer valves 24 and 25, air intake valves 38 and 39, and exhaust valves 56 and 51 can be -operated in any suitable manner in timed sequence with rotation of the crank shaft 22, it being only necessary that each valve open and close once during each two revolutions of the crank shaft. In the illustrated embodiment two cam shafts 11 and 18 lare provided, one for the left hand valves and one for the right hand valves. The two cam shafts 11 and 18 respectively carry gears 19 and 80 which mesh with a pinion 8| carried by the crank shaft 22 within the crank case 23. The gears 18 and 80 a're so correlated with the pinion 8| that one revolution of the crank shaft 22 will cause one-half revolution of the two cam shafts 11 and 18. In other words, the crank shaft 212 will make two complete revolutions to one revolution of the two cam shafts 11 and 18. To operate the two transfer valves 24 and 25, cams 82 and 83 are carried by the respective cam shafts 11 and 18 and these cams 82 and 83 operate tappets 84 and 85 respectively which connect with the cups 28 and 29 respectively for operating the two transfer valves 24 and 25. 'Ihe cam surfaces of the cams 82 and 83 extend through an arc preferably of approximately 180.

crank case 23 may be provided with a pulley 50 and a belt is shown as running over this Also carried respectively by the two cam shafts 11 and 18 are two cams 86 and 81 respectively which work against the lower arms of suitably pivoted bell crank levers 88 and 88 respectively,

the upper arms of which bear against the shanks 58 and 59 respectively of the respective exhaust valves 56 and 51. The cam surfaces of the cams 86 and 81 run through approximately 100.

Also vmounted on the respective cam shafts 1'| and 18 are cams 89 and 9| which operate tappets 92 and 93 respectively which run upwardly and bear` against the inner ends of rocker arms 94 and 95 respectively, suitably pivoted on brackets 96 and 91 respectively, and the inner ends of these rocker arms 94 y'and 95 bear against the shanks 40 and 4| respectively of the respective air intake valves 38 and 39. The cams 90 and 8| have cam surfaces which extend approximately through 140.

A fuel line for hydrocarbon fuel designated byv the numeral 98 and running from a source of fuel supply is shown in Fig. 2 as running to the twin fuel injector 14. Of course, the igniters 10 and 1| are connected to a suitable source of electricity as by the wires 99 and |00 shown in Fig. 2.

In Fig. 4 there is shown a diagram which illustrates a two cycle operation of the engine. This diagram shows the opening and closing movement of the exhaust valves, admission valves, injector nozzles, air intake valves and the igniters through two revolutions of the crank shaft. In this diagram it is considered that at the zero degree position of thel crank shaft 22, the piston I8 is at its extreme downward position in the cylinder 6. At the 180 position and at the 540 position the piston will be at its extreme limit of upward travel and at the 360 and at the '120 position the piston will be at its extreme limit of downward travel'. Of coursethe zero degree position and the '120 position coincide. The various valves are considered to be open during the period they are shown in the shaded or crosshatched position, and the injectors are considered to be forcing fuel through the spray nozzles 12 -and 13 during the period they are shown in the shaded or cross-hatched position.

` Operation In Fig. 1 of the drawings the engine is shown in position that the parts will assume shortly after the charge has been exploded in the left hand combustionchamber 1 and when the piston |9 is at its extremeupper position, In Fig. 3 the various ca ms are-shown in this same position. In describing-the operation of the engine in connection with the diagram shown in Fig. 4, it is assumed that at the 0 position shown in the diagram the piston |9 is at its extreme lower lposition with the crank shaft 22 positioned 180 behind the position shown in Fig. 1.

Considering '120 rotation of the crank shaft from such 0 position, starting with the piston at its extreme position o f downward movement, the various valves, injectors, and igniters operate as follows: At approximately the 5 position of rotation of the crank shaft the right transfer valve 25 closes, and the left transfer valve 24 opens while at the same time the right exhaust f valve 51 opens. At approximately 10 from the 0 position the right air intake Avalve 39 opens. At approximately the igniter 10 of the left combustion chamber is energized to explode the charge in the left combustion chamber, the explosion occurring just prior to the time that the piston |9A reaches its uppermost position at the .amarte 180 position of the crank shaft. At approximately the 265 position the exhaust valve 5i of the right combustion chamber closes. At approximately the 290 position the air intake valve 39 of the right combustion chamber closes. At approximately the 295 position the twin injector "i4 forces an injection of a charge of fuel to the right combustion chamber 8 through the right spray injector nozzle 73, the said injector nozzle 13 closing at approximately the 305 position. At approximately the 365 position immediately-after the first down stroke of the piston, the transfer valve 24 of the left combustion chamber i closes and the transfer valve 25 of the right combustion chamber 8 opens. Also at approximately the 365 position the exhaust valve 56 of the left combustion chamber? opens. At approximately the 370 position the air intake valve 38 of the left combustion chamber opens. At approximately the 510 position the igniter `II of the right combustion chamber 8 is energized to ignite the charge and explode the same in the right combustion chamber. The charge is exploded in the right combustion chamber shortly prior to the time that the piston I9 reaches the upper end of its travel on the second up stroke, or shortly prior to the 540 position. At approximately the 625 position the exhaust valve 56 of the left combustion chamber closes. At approximately the 650 position the air intake valve 38 of the left combustion chamber I closes. At approximately the 655 position the injector 14 forces a chargev of fuel through the left Vhand spray injector nozzle 'I2 into the left hand combustion chamber 7, the said injector nozzle closing at approximately the 665 position. l

On the first up stroke of the piston I9 from the position, closing of the right transfer valve 25 prevents communication between the head of the -cylinder 6 through the passage I8 and port I4 to the right hand combustion chamber 8 and opening of the left hand transfer valve 24 permits communication between the head of the cylinder S and the left hand combustion chamber '1. The products of combustion lying in the cylinder 8 from the previous explosion of the charge in the right hand combustion chamber 8 are accordingly forced by the piston during the rst up stroke thereof into the left hand combustion chamber 'I to mix with the air and liquid fuel already in that chamber, heat the same and to compress the l charge. During the first up stroke of the piston the exhaust valve in the right hand chamber opens and the air intake valve 39 opens. The

blower 48 forces fresh air through the conduit 49 A and air port 31 into the right .combustion chamber 8 to scavenge the products of combustion in this chamber through the exhaust port- 55 into the exhaust pipe 61 and to ll the combustion chamber 8 with fresh air. During the -first down stroke of the piston I9, the` exhaust valve 51 in` the right combustion chamber closes somewhat ahead of the closing of the right air intake valve 39 and as a result the air in the right combustion chamber 8 is placed under some initial compression by reason of the force of the blower 48.

As stated the charge in the left hand combustion chamber I is red just prior to the time that the piston reaches its extreme upper position during the first up stroke of the piston. As

the charge isred the exploded gases run through the transfer port I3 and left passage Il into the,

head of the cylinder 8, thereby forcing the piston downwardly to produce the first power stroke. During the rst down stroke of the piston and after both the exhaust valve and the intake-valve, 57 and 39 respectively, of the right hand combustion chamber 8 are closed, the nozzle i3 operated from the twin injector 74 forces a charge of fuel into the right hand combustion chamberV 8 to there mix with the air already in that chamber and under some initial compression.

During the second up stroke of the piston I9, the admission valve 24 of the left combustion chamber 'I closes to prevent communication between the head of the cylinder 6 and theleft y combustion chamber l through the passage I ll.

This occurs early in the upstroke and at the same time the transfer valve 25 of the right combustion chamber 8 opens so'as to afford communication between the head of the cylinder 6 and the right combustion chamber 8 through the passage I8 and'port I4.v On this second up stroke of the piston the products of combustion Within the cylinder 6 are forced into the right combustion chamber 8 through the passage I8 and port I4 imparting heat and compression to the mixed air and fuel already within the right hand combustion chamber 8. The hood 69 causes the productsA of combustion to be held chiefly outside of the hood which' is desirable in order to secure the best explosion of the charge, inasmuch as the richer mixture adjacent the injector nozzle 13 lies within the hood and the charge is ignited by the igniter 'Il located within the'hood. In other words, the hood 89 acts to .segregate to at least some extent vthe .fresh air and charge of fuel from the exhaust gases as exhaust gases are forced into the top of chamber 8.

' second up stroke the igniter 'II explodes the charge in the right combustion chamber 8.

' Also during the second up stroke of the piston I9 first the left exhaust valve 5B opens and shortly thereafter the left air intake valve 38 opens and the blower 48 then forces air through the conduit 49 and port 38 into the left combustion chamber 1 to scavenge the products of combustion Within the left combustion chamber 'I through the exhaust port` 84 into the exhaust pipe 66 and to ll this chamber with fresh air.

During the second down stroke of the piston I9,

. valve 38 closes.

first the left exhaust valve 58 closes and thereupon the action of the blower 48 places the air within the left combustion chamber under some initial compression whereupon the air intake As the right combustion chamber fires just before the 4piston I9 reaches its uppermost po-' sition during the second up'stroke, the gases of explosion run from the right hand combustion The transfer valve 25 of the right hand combus. tion chamber remains open until the early part of the up stroke of the next cycle of operation. It should be stated that as lthe products of combustionare forced by the piston I9 into the left vhand 'combustion chamber the hood 68 prevents them from mixing too greatly with the charge already in the chamber, as in the cas-e of the hood 68 in the right hand combustion chamber 8, but of course the addition of the said prod- Shortly-Ibefore thepiston I 9 reaches its extreme upper position during the ucts` of combustion imparts heat to the said charge and puts the same under some additional compression prior to firing.

The arrangement of the cups 28 and 29 carrying oil and Working over thecups 30 and 3l respectively act to maintain the stems 26 and 2l of the transfer valve 24 and 25 in cool condition so that they will not burn out. 'I'he fit between the cups 30 and 28 and 3l and 29 is not so close as to prevent .proper working of the valves by reason of vacuum action.

The hoods 58 and 69 in addition to separating the burnt gases from the fresh` air and fuel held within the hoods have the additional function of preventing any pre-ignition 4of the charge that might be brought on by the admission of the exhaust gases that are passed into the combustion chambers 1 and 8. This is true for the reason that as exhaust gases are admitted to the combustion chambers 8 and 9, the exhaust gases enter from the top and instead of coming directly into contact with the charge within the hoods. the exhaust gases tend to force the air ahead of them in the upper parts of chambers 8 and 9 down into the hoods and mixture of the exhaust gases with the charges of fuel is largely thus prevented by means of the hoods until the exhaust gases have given up most of their heat and sufficient of their heat to prevent ignition when they do come in contact with the fuel charged. -The blowing of fresh air into the combustion chambers l and 8 during the tim-e that the two valves 38 and 39 are open not only acts to scavenge the combustion chambers 'l and- 8 and supply fresh air for mixture with the fuel,v

but it also acts to cool the combustion chambers thereby producing an air cooled engine.

While the drawings illustrate merely a one cylinder engine it will, of course, be appreciated that the inventor contemplates the use of multicylinder engines embodying his invention,

In the modified form of the device shown in Fig. an engine casing B is employed including a cylinder having a head closure IDI within which' transfer ports |02 and |03 are formed controlled by transfer valves |04 and |05 respectively. A valve in head engine is thus provided. In other respects the engine shown in Fig. 5 is generally similar to' that previously described. The valve in head construction has some advantage over the construction shown in Figs. 1 to 4 for the reason that communication between the two combustion chambers and the head of the cylinder is more direct and, therefore, there is less loss of the compression forces of theexploded gases before they act on the piston.

It will, of course, be understood that the drawings are merely illustrative of the invention and that many variations may be made in the form, details, arrangement and proportions of the various parts without departure from the scope of the present inventionwhich, generally stated' consists in the matter shown and describedand set forth in the appended claims.

What is claimed is:

1. In an external combustion engine, a cylinder, a piston working therein, a crank shaft driven by said piston, first and second combustion chambers, means for injecting fuel into each chamber, means for exploding the charge in each chamber, means therefor for exhausting the spent gases from each chamber, means for injecting air into each chamber, each combustion chamber having communicationwith the head of said cylinder, first and second valves respectively controlling the communication between said vfirst chamber and said piston and said second chamber and said piston, means for operating said fuel injecting means, said exploding means, said exhausting means and said airinjecting means, and said valves in such manner that each are operated during two complete revo1u` tions of said crank shaft andthe combustion chambers are consecutively charged, fired and exhausted, the respective charging, firing and exhausting of one chamber following by two stroke intervals of the piston the respective charging, firing and exhausting of the other chamber, the first valve being open during substantially the entire time of the up stroke of the piston preceding the firing of the charge in the first combustion chamber and during substantially the entire down stroke of the piston following the firing of the charge of the first combustion chamber and said second valve being open during substantially the entire ltime of the up stroke of the piston preceding the firing of the charge in the second combustion chamber and during substantially the entire down stroke of the piston following the/firing of the charge in the second combustion chamber.

2. In an external combustion engine, a cylinder, a piston working therein, a crank shaft driven by said piston, first and second combustion chambers, means injecting fuel into each chamber, means for exploding the charge in each chamber, means for exhausting the spent gases from each chamber'while admitting fresh air under more than atmospheric pressure thereto, each combustion chamber having communication with the head of said cylinder, first and second valves respectively controlling the communicationvbetween said firstY chamber and said piston and said second chamber and said piston, means for operating said fuel injecting means, said exploding means, said exhausting and said fresh air admitting means and said valves in such manner that each are operated during two complete revolutions of said crank shaft and the combustion chambers are consecutively charged withI fuel, fired, exhausted, and charged with fresh hausting and charging with fresh air of one chamber following by two stroke intervals of the piston the respective charging of fuel', firing, exhausting and charging of' freshair of the other chamber, the first valve being open during substantially the entire time of one up stroke and the following down stroke of the piston and the second valve being open duringsubstantially the entire time of the next up stroke and the following next down stroke of the piston, the firing of the rst chamber occurring near the top of the up stroke of the piston when the first valve is open and the firing of the second chamber occurring near` the top of the up stroke of the piston when the second valve is open.

3. A two cycle external combustion engine hav-- ing in combination a cylinder, a piston working within the cylinder, a crank shaft driven from said piston, first and second combustion chambers having communication with the head of said cylinder, a source of air pressure, means affording communication between said source and each combustion chamber, a' source of fuel supply, in-

exhaust port in each chamber, an exhaust valve controlling each exhaust port, an air intake valve 2,375,756 for each chamber controlling the admission of ypiston, opening said injector of said second chamber shortly after the closing of4 said exhaust valve and intake valve of said second chamber during the second down stroke and'holding open the admission valve of said rst chamber during substantially the entire second down e ing the major portion of the strokes preceding and following the operation of the igniter in that chamber, causing the exhaust and air intake valves in each chamber to be maintained open during the major part of the down stroke and during a portion of the up stroke of thepiston following after the irst down stroke of the piston subsequent to the operation ofthe igniter in that .chamber and operating said injector 'for each chamber shortly after the exhaust and air intake valves ofthat chamber have been closed.

4. The structure defined in claim 3, the air intake valve of the respective chambers being located at one end thereof, the exhaust valve being located at the opposite end thereof, and there being a collecting truncated. cone between the air intake and the exhaust valves of each chamber aring inwardly from the exhaust valve end of the chamber toward the air intake valve, and the injector and igniter of each chamber being disposed within said cone.

5. An external combustion engine having in combination a cylinder, a piston working within the cylinder, a crank shaft driven from said piston, irst and second combustion chambers having communication with' the head of said cylinder, an air admission valve, an exhaust valve, a fuel injector and ignition means and a cylinder admission valve for each combustion chamber, said cylinder admission valves controlling the communication between the respective combustion chambers andthe head of said cylinder, means normally holding each of said valves closed, and means operating in timed sequence with said crank shaft for operating all of saidv valves and said two ignition means and said two injectors once each during each two rotations of said crank shaft, said last mentioned means during a rst up stroke of saidpiston holding the exhaust valve and the air intake valve of the rst chamber and the admission valve of said second chamber open during the major part of said rst up stroke and ring the ignition means of said second chamber shortly before the end ofthe stroke.

6. In an external combustion engine, a cylinder, a piston working therein, two combustion chambers having communication' with theV head of said piston, means for charging each combustion `chamber with fuel and air, means for exploding the charge in each combustion chamber, and means for exhausting the exploded gases from each chambenrtiming of the explosion of the charges in the two chambers being such that on successive up strokes of the piston charges in the two combustion chambers will alternately be exploded, a valve arranged betweenl each combustion chamber and the head of said cylinder controlling communication between thel same, and means for operating said valves in such manner that the respective valves for the two combustion chambers are open asthe chargeA in the respective combustion chambers are fired and are also open to permit the reception of the products of combustion from the exploded charge found in the cylinder to permit travel of the exploded products of combustion into the chamber which has not'iired on the up stroke of the piston following the power stroke created by the firing of the charge in the other combustion chamber and means for successively operating said charging means, said exploding means and said exhausting means for each chamber in timed sequence, each valve remaining open during the major part of one up stroke and the following down stroke and remaining closed during the major part of the next up stroke .and thenext following down stroke and one valve being open while the other is closed.

7. In an external combustion engine including in combination a cylinder, a piston working therein, a crank shaft driven by said piston, first and second combustion chambers, means for injecting fuel into the respective combustion chambers, means for injecting air into the respective combustion chambers, means -for exploding the charge in the respective combustion chambers, means for exhausting the spent gases from the respective `combustion chambers, valve means controlling communication between the respective combustion chambers and said cylinder, means rst up stroke, said last mentioned means holdving said exhaust valve and said intake valve of said rst chamber open during the rst part oi the rst down stroke of the piston, opening said injector of said rst chamber shortly after the closing of said exhaust valve and intakeV valve of said rst chamber during the rst down stroke and holding open the admission Vvalve of said second chamber during substantially the enthe rst part of the second down stroke of the 75 for operating said fuel injecting means, said air injecting means, said exploding -meansand said exhaust means in each combustion chamber once during two complete revolutions of the crank shaft and in opposite alternation on successive complete rotations of the crank shaft, and means for operating said two valve means in such manner that as the charge in the rst combustion chamber is red, the valve means' controlling communication between that combustion chamber and the cylinder is open `during the rst up stroke of the piston immediately proceeding the firing of the charge and during the down stroke of the piston immediately following the firing of the charge, and as the charge in thesecond combustion chamber is fired the valve means controlling communication between thesecond combusing the ring of the charge and during the down stroke of the piston immediately' foiiowing the firing of the charge,said first mentioned operat- 6 .s I n i ing means for respective'chambers acting to operate the fuel injecting means of that chamber during the rst up stroke prior to the operation of the charge exploding means for that chamber, being adapted to operate the charge exploding means for that chamber near the end of said first up stroke, being adapted to operate said air injecting means for that chamber and said exhausting means for that chamber during the second up stroke and part of the second down stroke. s'

8. An external combustion engine having in combination a cylinder, a piston working therein, a crank shaft driven by-:the piston, left and right combustion chambers, left and right transfer valves controlling communication between respective chambers and said cylinder, left and right air intake valves for the two chambers, left and right fuel injectors for the two chambers, left and right electrical igniters for the two chambers, left and'rightexhaust valves for the4 two chambers, means for supplying air under pressure to said airadmission valves, lmeans for supplying fuel to said fuel injectors, means for supplying electricity to said igniters, said piston moving successively through a first up stroke, a first down stroke, a second up stroke and a second down stroke to carry the 'engine through one complete sequence of operation, means for simultaneously opening said loft transfer valve and for closing said right transfer valve during the early part of said first up stroke and for closing said left-'transfer valve and for opening said right transfer valve during the early part of the second up stroke, means for opening said right exhaust valve and said right air intake valve during the early part of said first up stroke and for closing said right exhaust valve and said right intake valve during said first down stroke, means for y operating said right injector during a portion of said ilrst down stroke after said right exhaust' valve has been closed, means for opening said left exhaust valve and said left air intake valve during the early part of said second upstroke,

means for closing said left exhaust valve and said left intake valve during said second down- 

